Railway traffic controlling apparatus



Aug. 1, 1939; A J. M. PELIKAN 2,157,993

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Marph 20, 1937 2 Shets-Sheet 1 F 15 1M4]? c INVENTOR T 48 1 3 JolznMZzlmzz.

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H15 ATTORNEY Patented Aug. 1, 1939 UNITED STATES PATENT OFFICE RAILWAY TRAFFIG committee APPARATUS John M. Pelikan, Greentree, Pan;v assignoi to The- Union Switch & Signal Company; Swiss'vale, Pa., a corporation of Pennsylvania Application March 20, islet, serial 1:52.067

6 Claims. (61; 246 3") 1 My invention relates to railway traific controlling apparatus of the type involving switches and signals controlled by manually operable means, such, for example, as levers located at a control point, and has for an object the provision of means for accomplishing the control and indication for switches and signals with a minimum number of line wires between the control point and the controlled device.

I will describe several forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention for controlling and indicating a switch over a pair of conductors, comprising a switch control conductor and a common conductor, and for controlling and indicating one or more signals over a pair of conductors, comprising a signal control conductor and the same common conductor as is used for controlling a switch. Fig. 1A is a diagrammatic view showing a modification of the circuits for relays IWPR and lZRin Fig. 1, and also showing circuits for a switch indication relay lWAR. Fig. 2 is a diagrammatic view showing a modification of the control and indication circuits in Fig. 1. Fig. 2A isa diagrammatic view showing a modification of the circuits for relays lWPR and IZR. in Fig. 2. Fig. 3 is a diagrammatic View showing the ordinary release relays 211R, and lW-R'instead of the corresponding slow release relays in Figs. 1 and 2, and showing circuits for slow release repeater relays ZI-IRPR and IWRPR.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters 3 and 3a designate the track rails of a track section EF which is separated by means of insulated joints 4 from adjacent portions of a stretch of railway track. Track section EF is provided with a track circuit including a battery 5 connected across rails adjacent one end of the section and a track'relay TR. connected across the rails adjacent the opposite end" of the section. v V 7 Located in section EF is a track switch I. This switch is'op'erated' by a mechanism M which is controlled by a slow release polarized switch control relay IWR. v I

Adjacent the point E, signals ZRA and 2RB are located for governing trafiic movements over switch I froni'left toright as shown in the draw ings, which I will assume is the eastbound directioii'i Signal ELK, adjacent point F, is for governing westbound name movements over switch I in the normal position in which it is shown in the drawings. The signals are controlled in part by a slow release polarized signal control relay 5 ZI-IR;

in each (if the views, the contacts operated by the various'relays'or other devices are identified byriumbers'; such numbers having distinguishing prefixes from which they are sepa- 1'0 rated bya" clash when the contacts are shown apart from the relay or other device by which they are operated; The prefix for each of these contact" numbers comprises the reference charaicter' for the respective relay or other device. For example, contact lWR- n, shown in the operating circuits for switch mechanism M, is identified by, the number l2 separated by a dash from-theprefiii IWR which isthe reference characterfforre'lay IWR which this contact is cpe'rated; Similarly; ontacvzHRAL shown in the" operating circuits? for signals ZRA and ZLA, is identified by the; number 41 separated by a dash from the prefix ZHR" which is" the reference character for relay ZHR by which this contact'isop'erated. V

Switch control relay IWR and signal .control relay 2HRare manually controllable by devices such, for example, as levers" IV and 2V; respectively, located at'a control point which may be an interlocking tower or dispatchers ofiice. Each of these levers has a normal position 11,, in which it is shown in the' drawings, and a reverse position 1" to the right; Lever 2V has also a reverse position j'to theleft.

' The nor al and reverse energizing circuits for relay IWRinclude a switch control conductor 9 and a common conductor C. The normal and reverse energizing circuit for relay 2BR include a signal control conductor 30 and common con- 40 ductor C. I

The circuits for relays IWR and 2HR are supplied with current for energizing these relays from a suitable source, such, for example, as batteries IQ and 2Q located atthe control point. The positive terminal of battery 2Q and the negative terminal of battery IQ are connected together andwithcommon conductor'C. Battery IQ has apositive terminal B, and battery 2Q has a negative terminal N. '7

A polarized switch indication relay IWPR. is controlled by polar contact IS of switch control relay IWR, and by two pairs of pole changing contacts desi'gnatedby the reference characters M a' and M-b which are-operated in 'conjunc- 55 tion with switch I. Pair Ma comprises contacts I5 and I! which are closed at their back points only when switch I occupies the normal position in which it is shown in the drawings, and which are closed at their front points when switch I is moved away from the normal position. Pair Mb comprises contacts I8 and I9 which are closed at their front points when switch I is away from its reverse position, and which are closed at their back points only when switch I I occupies its reverse position.

Relay IWPR is energized by current of one pies a position corresponding to the position of polar contacts IWRI3 and IWR-.44 shown in the operating circuits for switch mechanism M. When switch I is between its normal and reverse positions, both pairs offcontacts M-a and Mb are closed at their front points, and hence relay IWPR will be shunted by either jumper 21 or 258, each ofwhich connects a front point of 'pair M-a with a front point of pair Mb.

When relay IWPR. is energized, a'switch indication repeater relay IZR is also energized by constant current, such, for example, as is supplied from terminal B of battery IQ, over the front point of contact 20 of relay IWPR. When relay IWPR is deenergized. relay IZR is energized by current. from terminal IB of a source of periodically interrupted current.

As here shown, periodically interrupted current is provided by passing current from terminal B, through contact 32 of a coding device D. Coding device D maybe of an oscillatory type operating at a low frequency of the order of 120 cycles per minute, and provided with a self-control contact 6, as well as with contact 32 for periodically interrupting the current supplied from terminal B, and also having a winding designated by the numeral I 26 corresponding to the frequency of operation of coding device D. The contacts of coder D are biased by a coil spring 'I to the position shown in the drawings, when the coder is deenergized. Coder D is connected directly with terminal C and, through its contact 6, is connected with terminal B, and is therefore constantly in operation.

The'switch control circuits for energizing relay I WR. include the winding of a second switch indication relay I WKR. in series with the winding of relay'IWR, and also include contact I ZR-II of relay iZR and contact I0 of a lock relay ILR. Relay ILR may be controlled by track relay TR and by an approach locking relay, or by any other means desired. Theapproach locking relay for controlling relay ILR'inay be controlled in'any suitable manner, such, for example, as shown for relay L in Letters Patent of 'the United States No. 1,956,851, granted May 1, 1934, to C. A. Brooks and J. M. Pelikan for Railway traflic controlling apparatus.

A signal indication relay ZI-IF is energized by periodically interrupted current supplied from terminal IB to circuits controlled by signal control relay 2HR and by signal repeater relays ZRGPR and 2LGPR. Relay ZLGPR is controlled by signal ZLA, and is energized only when signal ZLA is indicating stop. Relay ZRGPR is similarly controlled by signals 2RA and 2R3.

As here shown, signals ZRA, 2RB and ZLA are of the searchlight type, but may be of any other suitable design. As shown in. the drawings, each of these signals comprises a member 43 mounted to oscillate between two extreme positions, and controlled by a winding 42 and by a permanent magnet or an electromagnet, not shown, so that when winding 42 is energized, member 43 will move to one of its extreme positions or the other according as winding 42 is energized by current of normal or reverse polarity. Member 43 is biased to a middle position in which it is shown in the drawings, and which it occupies whenwinding 42 is deenergized. Member 43 carries three roundels G, R and -Y arranged to cooperate with an electric lamp 2 in such manner that 1 when member 43 is in its middle position, roundel W R is in front of lamp 2', whereas when member polarity or the other only when switch 'I ioccusuitable source of current and is, therefore, constantly lighted.

Each of the signals operates a contact 22 which is closed when the member 43 occupies the R or Y positions but is open when member 43 occupies the G position. Each of the signals 2RA andZLA also operates a contact 23 which is closed when the member 43 occupies the R or G position but is open when member 43 occupies the Y position. A signal of this type is disclosed and claimed in Letters Patent of the United States No. 1,864,224 granted to Wesley B. Wells on June 21, 1932, for Light signals.

The signal control circuits for energizing relay 2HR include thewinding of a second signal indication relay ZHKR in series with the winding of relay ZHR, and also include back contact 3i of the first signal indication relay 2HF.

The second switch indication relay IWKR controls an indication device here shown as an electric-lamp I K. The second signal indication relay ZHKR also controls an indication device here shown as an electric lamp 2K, 5 Referring next to Fig. 1A, relay ,IWPR is here controlled only by pole changing pairs Ma and M-b, and is, therefore, merely a switch repeater for switch I. In Fig. 1A, a switch indication relay IWAR is controlled by relays IWR and I WPR similarly to the manner in which relay IWPR in Fig. 1 is controlled by relay IWR and by switch I. ,In Fig. 1A, relay IZR'is controlled by relay *IWAR similarly to the manner in which relay IZR in Fig; 1 is. controlled by relay IWPR.

-In ,F'ig.f.2, the circuits for energizing relays IWR and I WPR are exactly like those shown in Fig. 1. Switch indication repeater relay I ZR shown in Fig. 2, is however, of the slow release type instead of the, ordinary type shown in Fig. 1. [A second slow release switch indication repeater relay IZPR, controlled by a front contact of relay IZR, is also shown in Fig. 2. The first circuit forrelay IZR is controlled by a front contact of relay IWPR. as in Fig. 1, but the second circuit for relay IZR is here energized by constant current, and includes a back contact of relay IZPR aswell as a back contact of relay IWPR.

Relay 2I-1F, in Fig. 2, is of the slow release type instead ofthe ordinary type shown in Fig. 1. Relay ZHR is here controlled by a front contact of relay 21-11 instead of by a back contact as in Fig. 1. In Fig. 2, relay ZHF is energized by current from terminal B, instead of by current from ter-, minal BI as in Fig. 1. Two circuits for relay ZI-IF are controlled by relays ZLGPR and 2RGPR in conjunction with a front contact and polar contacts of relay 2HR. A third circuit is added for relay 2HF controlled by a back contact of relay 2I-IR.

In Fig. 2A, as in Fig. 1A, relay IWPR is merely a switch repeater for switch I. The first slow release switch indication repeater relay IZR is here controlled by circuits including not only a front contact of relay IWPR, as in Fig. 2, but also including polar contacts of relays IWR and IWPR, and in some instances also including a back contact of relay IZPR. The circuit for relay IZPR, and the circuit for relay IZR through a back contact of relay IWPR, are exactly similar to the corresponding circuits shown in Fig. 2.

In Fig. 3, the slow release relays IWR and 2HR of Figs. 1 and 2 are replaced by ordinary relays which control slow release switch and signal control repeater relays IWRPR and ZHRPR, respectively. With this arrangement, the switch and signals can be controlled from a longer distance than is possible with the slow release line relays of Figs. 1 and 2. This is because the ordinary is lower with the ordinary relays than with the 7 slow release relays.

Having described, in general, each of the several forms of apparatus embodying my invention, I will now trace in detail the operation of these forms of apparatus.

As shown in the drawings, all parts are in the normal condition, that is, the switch and a signal control levers IV and 2V, respectively, are in their normal position n; switch I is in its normal position; signals 2RA, ZRB and ZLA are indicating stop; coding device D is operating; relays TR, ZRGPR, ZLGPR, IWR, IWPR, IZR, ILR and IWKR. are energized; relay IWAR of Fig. 1A, re-v lay ZHF of Fig. 2, relay IZPR, of Figs. 2 and 2A, and relay IWRPR of Fig. 3 are also energized;

relay ZHF of Fig. 1, relays ZHR and HIKE of the various figures, and relay ZHRPR of Fig. 3 are deenergized; switch indicating lamp IK is lighted, lamps 'z' of signals ZRA, ZRB and ZLA are lighted, and signal indication lamp 2K is unlighted.

I will first trace the operation of the form of apparatus shown in Fig. 1.

With switch control lever IV in its n position, switch control relay IWR is energized by current of normal polarity passing from terminal B,

: through contact 8 of lever IV, winding of relay IWKR, switch control conductor 9, contact I!) of relay ILR, contact IZR,I I, and the winding of relay IWR, to common conductor C. With relay lWR thus energized by current of normal polarity, the normal operating circuit for mechanism M is closed, passing from terminal B, through contacts iWRI2 and IWRI3, mechanism M, and contact IWR.I4 to conductor C. With relay IWR energized by current of normal polarity, and with switch I in the normal position, relay IWPR is energized by a circuit passing from terminal B, through the back point of contact I5 of pole-changing pair Ma, contact I6 of relay IWR, winding of relay IWPR, and back point of contact I? of pair Ma, to conductor C. With relay IWPR energized, relay IZR is also energized by its circuit passing from terminal B, through the front point of contact 20 of relay IWPR. Since the circuit for relay IWR is energized, relay IWKR which is in series with relay IWR is also energized, and hence switch indication lamp IK is lighted by its circuit passing from terminal B, through contact ZI of. relay IWKR.

With signals ZRA and ZRB indicating stop, signal repeater relay 2RGPR is energized by its circuit passing from terminal B, through contacts 22 and 23 of signal ZRA, contact 22 of signal 2RB,

and the winding of relay 2RGPR to conductor C.

With signal ZLA indicating stop, signal repeater relay ZLGPR is also energized by its circuit passing from terminal B, through contacts 22 and 23 of signal ZLA, and the winding or relay ZLGPR to conductor C.

I will assume that the leverman desires to reverse switch I. He will therefore move lever IV to its r position. Relay IWR will then be energized by current of reverse polarity passing from battery 2Q, through conductor C, winding of relay IWR, contact lZRr-ll, contact Ii! of relay ILR, conductor 9, winding of relay IWKR, and contact 8 of lever IV in the right-hand position, to terminal N. With relay IWR energized by current of reverse polarity, switch I will be operated to the reverse position by its circuit passing from terminal B, through contact IWRI2, contact IWRI3 in the reverse position, mechanism M, and'contact IWRI4 in the reverse position, to conductor C.

With relay IWR energized by current of reverse polarity, contact N5 of relay IWR will open the circuit previously traced for relay IWPR, causing relay IWPR; to become deenergized. With relay IWPR deenergized, relay EZR. will be energized by periodically interrupted current passing from terminal IB, through the back point of contact 20 of relay I WPR, and the winding of relay IZR to conductor C. With relay lZR periodically energized, contact IZH-II operated by this relay will be closed periodically, and hence the circuit for relays IWKR and IWR will be closed only periodically. Relay IWKR will therefore be periodically deenergized, causing the circuit for lamp IK to'be periodically opened, and

hence lamp. IK will display a flashing indication.

When switch I starts to move, contact pair Ma will close at its front points, thereby completing a circuit for relay IWPR through the shunt connection-28, and thereby preventing relay lWPR from becomingenergized in any manner while switch I is Icetween'its normal and reverse positions.

When switch I completes its movement and locked in the reverse position, contact pair Mb will close at its back points, thereby opening the circuit through the shunt connection 28. With pair M-a now closed at its front points and pair Mb closed at its back points while contact IE3 of relay IWR is closed in the reverse position, a

second energizing circuit will be completed for relay IWPR, passing from terminal B, through the back point of contact I8 of pair M-b, winding of relay IWPR, contact I6 of relay IWR in the reverse position, and back point of contact I9 of pair Mb, to conductor C.

Relay IWPR, upon thus becoming energized, opens the circuit for relay IZR. which is supplied with periodically interrupted current through the back point of contact 20 of relay IWPR, and again closes the circuit supplying relay IZR with constant current, from terminal B, through the front point of contact 20 of relay IWPR. Relay lZR being again constantly energized, contact IZR.II will be constantly closed, causing relay IWKR to be constantly energized and switch indicating lamp IK to be constantly lighted. When lamp IK thus stops flashing, the leverman will known that switch I has completed its movement and is locked in its reverse position in response to the energization of relay IWR by current of reverse polarity.

I will assume that the leverman now desires to return switch I to the normal position. He will therefore return lever IV to its n position, causing relay IVVR to again become energized in the normal direction by the circuit first traced for this relay. The second circuit traced for energizing relay lWPR'will not be opened at contact "5 of relay IWR, causing relay IWPR to again become deenergized. With relay IWPR again deenergized, relay I ZR will again be periodically energized, causing relay IWKR to be periodically energized, which, in turn, will cause switch indicator lamp lK to display a flashing indication.

I will next assume that, with switch I again in its normal position, the leverman desires to clear signal 2LA. He will therefore move lever 2V to its 1" position, causing relay ZHR to become energized by current of reverse polarity passing from battery 2Q, through conductor C, winding of relay 2BR; contact 3| of relay ZHF, conductor 30, winding of relay 2HKR, and contact 29 of lever 2V in its right-hand position to terminal N. Completion of this circuit causes relay ZHKR. to close its contact 3'5, thereby completing a circuit passing from terminal B, through contact 31, for lighting signal indication lamp 2K.

With relay ZHR energized by current of reverse polarity, a circuit is completed for periodically energizing relay ZHF by current passing from terminal IB, through contact ZLGPR-34, contacts 35 and 35 of relay ZHR, and the Winding of relay 2I-IF to conductor C. Relay 2HF, being periodically energized, will periodically open its contact 3| in the circuit previously traced for relays ZHKR and ZHR, causing contact 31 of relay ZHKR to be periodically opened. Lamp 2K will, therefore, display a flashing indication.

With relay ZHR energized by current of reverse polarity, a circuit will be completed for causing signal 2LA to be operated to its Y or G position which may be selected in accordance with traffic conditions in advance. Only a portion of this circuit is shown, including contacts W38, lWR-39, 2HR'-48, 2HR4| in the right-hand position, and winding 42 of signal ZLA to conductor C. Upon the operation of signal ZLA to its G or Y position selected in accordance with trafiic conditions in advance, contact 22 or contact 23 of signal 2LA will open, causing relay ZLGPR. to become deenergized. With relay ELGPR deenergized, contact 2LGPR--34, operated by this relay, will open the circuit previously traced for relay ZHF, and hence contact 3| of relay ZHF will be constantly closed, causing relay EHKR to be constantly energized, which, in turn, causes lamp 2K to be constantly lighted.

If the form of apparatus shown in Fig. 1 is modified as shown in Fig. 1A, switch indication relay iWAR is normally energized by a circuit passing from terminal B, through contact 44 of relay IWR, contact 45 of relay IWR in the lefthand position, contacts 4% and 41 of relay IWPR, and the winding of relay l WAR, to conductor C. With relay lWAR thus energized, relay IZR. is energized by constant current passing from terminal B, through the front point of contact 48 of relay lWR, and the Winding of relay IZR, to conductor C. Switch indication lamp IK will therefore be constantly lighted.

If now the leverman causes relay lWR to be energized by current of reverse polarity in order to reverse switch I, the circuit traced for relay IWAR will be opened at contact 45 of relay IWR,

causing relay IWAR to be deenergized. With relay IWAR deenergized, relay I ZR will be periodically energized by current passing from terminal IB, through the back point of contact 48 of relay IWAR, and the winding of relay IZR, to conductor C. With'relay IZR thus periodically energized, contact iZR-ll in the circuit previously traced for relay IWR will periodically open, causing relay IWKR to be periodically deenergized and, in turn, causing lamp IE to display a flashing indication until switch I is locked in the reverse position, which causes relay IWPR to reverse its contact 46 to agree with contact 45 of relay IWR.

In the form of apparatus shown in Fig. 2, relay lWR is energized by circuits which are exactly similar to the circuits shown for this relay in Fig. 1. The circuits for relay IWPR are also exactly like those for relay IW'PR. in Fig. l. The first circuit for relay IZR, including the front point of contact 20 of relay IWPR, is also exactly like the circuit for relay IZR through the front point of contact 2!} of relay lWPR in Fig. l. The second slow release switch indication repeater relay I ZPR is energized by a circuit passing from terminal B, through contact 49 of relay IZR. With contact 20 of relay IWPR closed at the front point, relay IZR is constantly energized and, in turn, relay IZPR is also constantly energized,

If the leverman should reverse lever IV, causing relay lWR to be energized by current of reverse polarity, relay IWPR will become deenergized, causing relay IZR to, in turn, also become deenergized. With relay IZR deenergized, relay lZPR will likewise be deenergized. When contact 53 of relay I ZPR closes, a circuit will be completed for again energizing relay i ZR, passing from terminal B, through contact 50 of relay IZPR, back point of contact 2% of relay iWPR, and the winding of relay IZR, to conductor C. Energization of relay IZR causes relay IZPR to again become energized, which opens the circuit traced for relay IZR through contact 56 of relay IZPR. Relays S212. and IZPR will thus be alternately energized and deenergized as long as relay iWPR, is deenergized. Contact lZR-ll will therefore be periodically opened in the circuit for relay lWR, causing switch indication lamp IK to display a flashing indication.

As soon as switch I completes its operation in response to the reverse energization of relay lWR and is locked in its reverse position, relay IWPR will again become energized by the second circuit traced for energizing relay IWPR in the form of apparatus shown in Fig. 1. The switch indication lamp lK will then again display a steady indication. 7

As already pointed out, relay ZHF in Fig. 2 is of the slow release type, and is controlled by the back point of a contact of relay ZHR, as well as by the front point of this contact. Relay 2BR is controlled by a front contact of relay 2HF instead of by a back contact of this relay as in Fig. 1. Relay ZHF is here energized by constant current supplied directly from terminal B, instead of by periodically interrupted current supplied from terminal IB in Fig. 1. With relay 2HR deenergized, as shown in the drawings, relay 2I-IF is normally energized by a circuit passing from terminal B, through the back point of contact 55 of relay ZHR, and the winding of relay 2HF to conductor C.

If, with the apparatus as shown in Fig. 2, the leverman moves lever 2V to the r position for clearing signal 2LA, relay ZHR will become energized by current of reverse polarity, as described for Fig. 1, thereupon opening its contact 55 at the back point and closing this contact at the .front point. Upon the lapse of a'brief period of time required because relay-23H? is slow releasing,

contact 5| of relay 2HF will open thecircuit for relay ZHR. Since relay ZHR, is slow releasing, the front contacts of this relay Will not open immediately. Before the front contacts of relay 2BR have had time to open, signal ZLA will have cleared and opened the circuit for signal repeater relay -2LGPR. Contact 5.3 of relay ZLGPR, will thereupon complete a second circuit for energizing relay ZHF, passing from terminal B, through contact .53 of relay ZLGPR, contact 5d of relay -2HR, in the rightehand position, front point of contact 55 of relay 2BR, and the winding of relay 21-115 to conductor C.

It follows that, with the apparatus as shown in Fig. 2, signal indication lamp 2K will first become lighted on account of the energization of relay 2HKR when the circuit for relay ZHR is closed, and will then be extinguished during the interval of time between the opening of contact 5-] of relay 2HF, when relay 2I-IR opens contact 55 at the back point, and the subsequent closing of contact 5| of relay ZI-IF, when contact 53 of relay ZLGPR completes the second circuit for relay ZI-IF.

In Fig. 2A, the circuits for relay IW'PR are exactly similar to the circuits shown for this relay in Fig, 1A. Relay IZR is normally energized by a circuit passing from terminal B, through contact 45 of relay lWR in the left hand position, contact &5 of relay IWPR in the lefthand position, front point of contact 25 of relay IWPR, and the winding of relay IZR, to conductor C. With relay IZR energized, relay IZPR is energized by a circuit passing fromterminal B, through contact 49 of relay IZR, and the winding of relay EZPR, to conductor C.

If the leverman should desire to reverse switch I, he will move lever IV to its r position, causing relay IWR to be energized by current of reverse polarity. The circuit just traced for relay IZR will therefore be opened at contact 45 of relay IWR, and hence contact 49 of relay IZR will open the circuit for relay lZPR. With relay EZPR. deenergized, a second circuit will be completed, after a brief period of time, for energizing relay IZR, passing from terminal B, throughcontact 45 of relay IWR. in its right-hand position, contact lZPR,55, and thence by the circult previously traced for relay IZR. through contacts 55 and 2B of relay lW'PR. Relay IZR, being again energized, causes relay lZPl't to again become energized and open the circuit traced for relay IZR, through contact IZPR-iiii. In this way, relays iZR and lZPR. are alternately energized and deenergized, causing contact iZRa-H,

shown in Fig. 2, to be periodically opened in the circuit for relays lWKFt and IWR.

When switch I moves away from its normal position in response to the reverse energization of relay IWR, relay IWPR. will become deenergized, causing contact 2%) of relay iWPR to become closed at its back point. Ihe action of relays EZR. and IZPR. "will now be exactly the same as traced in connection with Fig. 2, until switch i is locked in its reverse position. Athird iZR,

point of contact 20 of relay IWPR, and the winding of relay IZR, to conductor C.

In Fig. 3, relays lWR and 2HR are ordinary acting polarized relays instead of slow release relays as in Figs. 1 and 2. The slow release polarized switch and signal control repeater relays IWRPR and ZHRPR are controlled by relays IWR and ZI-IR, respectively, and relays IWRPR and ZHRPR similarly control/circuits which are similar to those controlled by relays IWR. and

ZHR, respectively, in the apparatus of Figs. 1 and 2.

With relay IWR energized in the normal direction as shown in Fig. 3, relay IWRPR is energized by a circuit passing from terminal B, through contact 57 of relay IWR, contact 59 of relay IWR closed in the left-hand position, winding of relay IWRPR, and contact 58 of relay !WR closed in the left-hand position, to conductor C. When the leverman causes relay IWR to be energized in the reverse direction, relay lWRPR will be energized by current of reverse polarity passing from terminal B, through contact 51 of relay IWR, contact 59 of relay IWR in the right-hand position, winding of relay IWRPR, and contact 58 of relay IWR in the.

right-hand position, to conductor C.

When the leverman causes relay ZHR to be energized by current of reverse polarity for clearing signal 2LA, relay ZI-IRPR will become energized by current passing from terminal B, through contact 640i relay 2BR, contact 65 of relayZI-IR. inthe right-hand position, winding of relay ZHRPR, and contact 65 of relay ZI-IR in the right-hand position, to conductor C. When the leverman causes relay ZHR. to be energized by current of normal polarity, relay 2HRPR will be energized by current of normal polarity, passing from terminal B, through contact 64 of relay ZHR, contact 66 of relay 2HR in the left-hand position, winding of relay 2I-IRPR, and contact 65 of relay'2I-IR in the left-hand position, to conductor C.

From-the foregoingdescription and the accompanying drawings, it follows that in apparatus embodying myinvention, operations of a track switch are governedby a switch control circuit including a switch control conductor and a common-conductor, and that a switch indication device is controlled by indication circuits which also include the same switch control conductor and the same commonconductor. A constant indication is displayed while the switch occupies the position which corresponds: to the condition of energization of its control circuit. A periodically interrupted indication is displayed while the switch is out of correspondence with the condition of energization of its control circuit.

.Signal control circuits, including a signal control conductor and the same common conductor as is usedin'the switch control and indication circuits,-govern the clearing of one or more signals. A signal indication device is controlled by indication circuits which include the signal control conductor and the common conductor. In one form of apparatus embodying my invention, the signal indication device is periodically operated from thetime the signal control relay is energized until the signal corresponds to the condition of energization of the signal control relay. In a second form of apparatus embodying my invention, there-is a single. interruption of the signal indication device when a signal is being cleared. The signal indication device is operated constantly as soon as the signal corresponds to the condition of energization of the signal control relay.

Although I have herein shown and described only a few forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, an electrically controllable device operable to a first and a second position, a polarized control relay selectively responsive to current of normal and reverse polarities for closing its polar contacts in normal and reverse positions respectively, means controlled by said polarized control relay for operating said electrically controllable device to its first or its second position according as the polar contacts of said polarized control relay are closed in the normal or reverse position respectively, an indication relay, circuits controlled by said polarized control relay and by said electrically controllable device for energizing said indication relay only if said electrically controllable device is in a position corresponding to the closed position of the polar contacts of said polarized control relay, a repeater relay, a circuit controlled by a front contact of said indication relay for energizing said repeater relay by constant current, a second circuit controlled by a back contact of said indication relay for energizing said repeater relay by periodically interrupted current, manually controllable circuits controlled by a front contact of said repeater relay for energizing said polarized control relay by current of normal and reverse polarities, and indication means controlled over said manually controllable circuits by said repeater relay.

.2. In combination, an electrically controllable device operable to a first and asecond position, a polarized control relay selectively responsive to current of normal and reverse polarities for closing its polar contacts in normal and reverse positions respectively, means controlled by said polarized control relay for operating said electrically controllable device to its first or its second position according as the polar contacts of said polarized control relay are closed in the normal or the reverse position, an indication relay, circuits controlled by said polarized control relay and by said electrically controllable device for energizing said indication relay only if said electrically controllable device is in a position corresponding to the closed position of the polar contacts of said polarized control relay, a repeater relay, a circuit controlled by a front contact of said indication relay for energizing said repeater relay, a second repeater relay, a circuit controlled by a front contact of said first repeater relay for energizing said second repeater relay, a second circuit for energizing said first repeater relay controlled by a back contact of said indication relay in series with a back contact of said second repeater relay, manually controllable circuits controlled by a front contact of said first repeater relay for energizing said polarized control relay by current of normal and reverse polarities, and indication means controlled over said manually controllable circuits by said first repeater relay.

3. In combination, an electrically controllable device operable to a first and a second position, a polarized control relay selectively responsive to current of normal and reverse polarities for 0 0 ing its polar contacts in normal and reverse positions respectively, means controlled by said polarized control relay for operating said electrically controllable device to its first or its second position according as the polar contacts of said polarized control relay are closed in the normal of the reverse position, a repeater relay, a circuit controlled by said polarized control relay and by said electrically controllable device for energizing said repeater relay only if said electrically controllable device is in a position corresponding to the closed position of the polar contacts of said polarized control relay, a second repeater relay, a circuit controlled by a front contact of said first repeater relay for energizing said second repeater relay, a second circuit controlled by a back contact of said second repeater relay for energizing said first repeater relay if said electrically controllable device is out of correspondence with said polarized control relay, manually controllable circuits controlled by a front contact of said first repeater relay for energizing said polarized control relay by current of normal and reverse polarities, and indication means controlled over said manually controllable circuits by said first repeater relay.

4. In combination, an electrically controllable device operable to a first anda second position, a polarized control relay selectively responsive to current of normal and reverse polarities for closing its polar contacts in normal and reverse positions respectively, means controlled by said polarized control relay for operating said electrically controllable device to its first or its second position according as the polar contacts of said polarized control relay are closed in the normal or the reverse position, a repeater relay, a second repeater relay, a circuit controlled by said polarized control relay and by said electrically controllable device for energizing said first repeater relay only if said electrically controllable device is in a position corresponding to the closed position of the polar contacts of said polarized control relay, a second circuit controlled by said polarized control relay and by said electrically controllable device and also by said second repeater relay for energizing said first repeater relay when said second repeater relay is deenergized while said electrically controllable device is out of correspondence with said polarized control relay, a third circuit controlled by a back contact of said second repeater relay for energizing said first repeater relay while said electrically controllable device is between its first and second positions, a circuit controlled by a front contact of said first repeater relay for energizing said second repeater relay, manually controllable circuits controlled by a front contact of said first repeater relay for energizing said polarized control relay by current of normal and reverse polarities, and indication means controlled over said manually controllable circuits by said first repeater relay.

5. In combination, an electrically controllable device operable to a given condition, a control relay, a manually controllable circuit for operating said control relay, means controlled by said control relay upon becoming operated for operating said electrically controllable device to said given condition, an indication relay, an indication circuit including a contact controlled by said electrically controllable device normally closed for energizing said indication relay but becoming opened when said electrically controllable device in response to operation of said control relay starts operating to said given condition, an indication repeater relay, means controlled by a front contact of said indication relay for constantly energizing said indication repeater relay, means controlled by a back contact of said indication relay for periodically energizing said indication repeater relay, a contact of said indication repeater relay included in said manually controllable circuit for preventing energization of said control relay whenever this contact is open, and indication means controlled over said manually controllable circuit by said contact of the indication repeater relay.

6. In combination, a railway track switch, a polarized control relay, a manually controllable circuit for energizing said relay by current of normal or reverse polarity for operating its polar contacts to its normal or reverse position respectively, means controlled by polar contacts of said relay when operated to said normal or reverse position for operating said switch to its normal or reverse position respectively, an indication relay, means controlled by said polarized control relay and by said switch for energizing said indication relay only when said switch and the polar contacts of said relay occupy corresponding positions, an indication repeater relay, means controlled by a front contact of said indication relay for constantly energizing said indication repeater relay, means controlled by a back contact of said indication relay for periodically energizing said indication repeater relay, a contact of said indication repeater relay included in said manually controllable circuit for preventing energization of said control relay whenever this contact is open, and indication means controlled over said manually controllable circuit by said contact of the indication repeater relay.

JOHN M. PELIKAN. 

